<div  class="d-flex align-items-center login-content justify-content-center a">
    <form [formGroup]="myForm" (ngSubmit)="onSubmit(myForm.value)">
      <h3 class="d-flex justify-content-center">用户登录</h3>
      <p *ngIf="myForm.invalid" class="text-dange">表单无效！</p>
      <p>{{name$ | async}}</p>
      <div class="form-group">
        <label for="userName">用户名</label>
        <input type="text" class="form-control" id="userName" aria-describedby="输入用户名" name="userName" 
        [formControl]="userName" [ngClass]="{'is-invalid':userName.invalid,'is-valid':userName.valid}">
        <div class="valid-feedback">
          用户格式正确！
        </div>
        <div class="invalid-feedback">
         用户名必须在3~20位之间
        </div>
      </div>
      <div class="form-group">
        <label for="password">密码</label>
        <input type="password" class="form-control " id="password" aria-describedby="输入密码"name="password" 
        [formControl]="password" [ngClass]="{'is-invalid':password.invalid,'is-valid':password.valid}">
        <div class="valid-feedback">
          密码填写正确！
        </div>
        <div class="invalid-feedback">
            用户名必须在6~16位之间
        </div>
      </div>
      <button type="submit" class="btn btn-primary btn-block">提交</button>
    </form>
  </div>